title: Absorptive chemistry based extraction for LC-MS/MS analysis of small molecule analytes from biological fluids - an application for 25-hydroxyvitamin D.
abstract: BACKGROUND
  Already available sample preparation technologies for liquid chromatography-tandem mass spectrometry have substantial shortcomings with respect to automation. A novel approach is based on gel-like polymeric material with defined absorption chemistry, which is immobilized in micro-plate wells. It is referred to as Tecan Immobilized Coating Extraction™ (TICE™) technology and it enables easy automation on liquid handling systems. We aimed to study the performance of Tecan AC Extraction Plate™ based on this principle by addressing 25-hydroxyvitamin D (25OHD) as an exemplary analyte.
  
  
  METHODS
  A protocol for extraction of 25OHD from serum samples based on TICE™ technology was implemented on a robotic liquid handling system Freedom EVO® (Tecan). An isotope-dilution ultra-performance liquid chromatography-tandem mass spectrometry method was used for quantification. Performance was tested according to a comprehensive protocol.
  
  
  RESULTS
  Linearity was found over a range from 4.3 to 65.8 ng/mL for 25OHD3. The coefficients of variation for the intra-day and inter-day precision were <6% and accuracy ranged between 96.9% and 99.8% for 25OHD3. Recovery was 84% and efficient control of matrix effects was verified. High sample throughput could be observed with 96 samples prepared in <60 min. Close agreement of results was found for clinical samples analyzed with a second tandem mass spectrometry method based on protein precipitation and two-dimensional ultra-performance liquid chromatography for sample preparation (r=0.988, n=73).
  
  
  CONCLUSIONS
  The new TICE™ technology was found to be a useful process for sample preparation in clinical mass spectrometry. Full automation suited for routine analysis was achieved.
authors.forename: Silvia
authors.initials: S
authors.lastname: Baecher
authors.forename: Roland
authors.initials: R
authors.lastname: Geyer
authors.forename: Christine
authors.initials: C
authors.lastname: Lehmann
authors.forename: Michael
authors.initials: M
authors.lastname: Vogeser
mesh_terms: D000042:Absorption; D001774:Blood Chemical Analysis / Q000295:instrumentation / Q000379:methods*; D002138:Calibration; D002853:Chromatography, Liquid; D006801:Humans; D057230:Limit of Detection; D016014:Linear Models; D011786:Quality Control; D053719:Tandem Mass Spectrometry; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D